supererogation

English speakers took "supererogation" from the Medieval Latin verb supererogare, which means "to perform beyond the call of duty." That Latin word, in turn, derives from the prefix super-, meaning "over and above," plus erogare, meaning "to expend public funds after asking the consent of the people." The earliest English uses of "supererogation" occurred in religious contexts, where it often referred to the doing of good deeds beyond those required for salvation. By the late 1500s, "supererogation" was being applied to any act performed above and beyond obligation.